The proposed research seeks to study characteristics of disasters that may affect mental health. The role of the duration of threat, the origin of threat (i.e., whether a disaster is a natural or human-made emergency) and the effects of blame, control, and mental health history in generating mental health and stress-related consequences will be examined. Five hundred subjects drawn from areas victimized by disasters varying along these dimensions, as well as from comparison (nonvictimized) sites will be studied, and broad-based measures of the prevalence and intensity of chronic psychological and stress effects will be collected. Analyses will be directed toward evaluating the role of these dimensions in producing chronic effects. The proposed research will provide comparative data on several types of disasters, provide important information about the differences between natural and human-made disasters, and provide useful information about disaster characteristics that will help plan mental health service delivery by providing better understanding of the needs of communities victimized by different disasters.